Rent is the biggest bill most people share and the one with the least room for error. The usual arrangement is that one flatmate pays the landlord and spends the first week of every month collecting from the others. It works until that person goes on holiday, or until someone pays four days late and nobody says anything.

One pot, three standing orders

Open a pot for the flat. Each flatmate sets a standing order into it for the 28th: their share of the rent plus their share of the bills. On the 1st the pot pays the landlord, and the broadband and the energy leave it by direct debit through the month.

Uneven rooms

The box room should not cost the same as the one with the bay window. Agree a split once, for example 38 % · 34 % · 28 % of £2,340, and write it into the pot. The shares are then £889.20, £795.60 and £655.20, and nobody recalculates them.

Bills that move

Energy is higher in January. Set the standing orders £25 over the average and let the pot build a cushion. Once it holds a full month of bills, stop the top-up.

• The feed shows who has paid in, so nobody has to ask
• A reminder goes out on the 27th to anyone whose share is missing
• One flatmate leaving does not break anything: swap the name, keep the pot

Nobody should be the flat's accountant. That job belongs to the pot.

The shared shelf

Washing-up liquid, bin bags, the olive oil. Put £10 a month each into the same pot and pay for house things with the card set to it. The receipts sit in the feed for anyone who wants to check.

Moving out

Close the pot and the balance returns in the same proportions it came in. The deposit follows the same split when the landlord pays it back.